基于蒙特卡罗模拟的光纤浊度传感器

Optical Fiber Turbidity Sensor Based on Monte Carlo Simulations

在后向散射式浊度测量方法的基础上,采用光纤传感技术,设计了一种Y形光纤束探头结构的浊度传感器,并在光纤束探头前端配置平面镜作为光反射配合目标。根据朗伯比尔定律通过实验研究了消光系数与浊度的线性关系,基于蒙特卡罗法建立了待测液中的光子散射模型,模拟不同检测情形下的传感器接收光强,优化得到光纤束到平面镜的最佳距离。标定接收光强与消光系数的关系曲线用于测量。此法简单高效,能检测消光系数低至0.059cm-1的水质,平面镜的有效使用将传感器灵敏度提高10倍以上。此传感器可用于便携式检测,结合空分和时分复用技术可实现在线监测。

Based on the backscattering turbidity measurement method, a turbidity sensor with Y-shaped optical fiber bundle probe structure in conjunction with a plane mirror is designed by using the optical fiber sensor technology. Turbidity is estimated in terms of total interaction coefficient, a parameter that contains strong signature of the turbidity of a solution. A scattered light model based on Monte Carlo simulations is applied to estimate the power collected by the fiber optic probe. The turbidity sensor is simple, and it＇s useful for detecting suspended impurities even in small quantities within a liquid, the total interaction coefficient of which is as low as 0. 059 cm^-1. With the reasonable use of the mirror, the sensitivity of the sensor is improved more than 10 times. The proposed sensor can be used for the portable measurements and the on-line monitoring can be realized by combining the space-division multiplexing technology and time-division multiplexing technology.